System and Method for Comprehensive Fracturing Pump Operation Monitoring

ABSTRACT

A system for monitoring a hydraulic fracturing pump includes a first sensor configured to measure a discharge fluid pressure of the pump, a second sensor configured to sense a displacement of a crankshaft of the pump, a processor communicatively coupled to the first and second sensors and configured to analyze the sensor data and determine a cycle count, duty cycle, and operating hour value for the positive displacement pump, and a display coupled to the processor configured to display the cycle count, duty cycle, and operating hour value.

FIELD

The present disclosure relates to sensors and monitoring devices and systems, and in particular, to a system and method for comprehensive fracturing pump operation monitoring.

BACKGROUND

Hydraulic fracturing is a process to obtain hydrocarbons such as natural gas and petroleum by injecting a fracking fluid or slurry at high pressure into a wellbore to create cracks in deep rock formations. The hydraulic fracturing process employs a variety of different types of equipment at the site of the well, including one or more positive displacement pumps, slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), wellhead, valves, charge pumps, and trailers upon which some equipment are carried.

Positive displacement or reciprocating pumps are commonly used in oil fields for high pressure hydrocarbon recovery applications, such as injecting the fracking fluid down the wellbore. A positive displacement pump may include one or more plungers driven by a crankshaft to create a high or low pressure in a fluid chamber. A positive displacement pump typically has two sections, a power end and a fluid end. The power end includes a crankshaft powered by an engine that drives the plungers. The fluid end of the pump includes cylinders into which the plungers operate to draw fluid into the fluid chamber and then forcibly push out at a high pressure to a discharge manifold, which is in fluid communication with a well head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of an exemplary embodiment of a system and method for comprehensive monitoring of a positive displacement pump according to the teachings of the present disclosure; and

FIG. 2 is a pictorial representation of an exemplary positive displacement pump as an exemplary monitoring subject for a system and method for comprehensive monitoring according to the teachings of the present disclosure.

DETAILED DESCRIPTION

The system and method for comprehensive monitoring may be used on a number of different pieces of equipment commonly found at a hydraulic fracturing site, such as positive displacement pumps, slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), charge pump (which is typically a centrifugal pump), trailers upon which some equipment are carried, valves, wellhead, conveyers, and other equipment. It is desirable to monitor the operation of these equipment so that timely inspection, maintenance, and replacement can be scheduled to ensure optimal operations. The system and method described herein can be used to monitor the operations of these different types of equipment used for hydraulic fracturing. Currently, no reliable data is available relating to the operations of these equipment so that equipment servicing tasks can be scheduled in a timely and optimal manner. Further, operation data can be easily falsified to benefit from warranty programs if no accurate data is available.

FIG. 1 is a simplified block diagram of an exemplary embodiment of a system and method 100 for comprehensive monitoring of a positive displacement pump according to the teachings of the present disclosure. The system 100 includes a microcontroller or microprocessor 102 (hereinafter referred to as a microcontroller) that is coupled to and receives pressure measurements from a sensor such as a pressure transducers 104 disposed in one or more locations on the pump (shown in FIG. 2) that can sense the discharge fluid pressure. The sensor may be alternatively disposed in a discharge fluid passageway in the pump. In addition to the pressure signal, the microcontroller 102 also receives a cycle signal from a sensor 106 configured to sense crankshaft displacement, such as a reed switch, Hall Effect sensor, or inductive proximity sensor. The microcontroller 102 is configured with software that is able to compute or determine a cycle count number from the cycle signal. A number of sensor devices may be incorporated in the system 100 to monitor and measure pump operational parameters that may be used to arrive at the desired three outputs of cycle count, duty cycle, and operating hour value. Examples of these sensors include: strain gauge (e.g., mounted on the metal housing of the fluid end of the pump to sense and measure the amount of flex in the housing due to pressure fluctuations of the fluid inside the fluid end), pressure sensor, accelerometer, vibration sensor, piezoelectric element, proximity sensor, linear variable displacement transducer (LVDT), load cell, and flow meter. The system 100 may include one or more of these sensors/devices. Pressure could also be obtained by using load cells located in close proximity to the bore but not necessarily in direct contact with the frac fluids.

The microcontroller 102 includes or is in communication with non-volatile memory devices 108 such as a FRAM (ferroelectric random-access memory) and flash memory. Alternatively, a memory device located externally, such as a flash drive or an SD card, may be used to store data from the microcontroller 102. The microcontroller 102 also receives an accurate real-time clock signal from a real-time clock 110. The microcontroller 102 is coupled to a display 112, which is used to present the hour, cycle count, and duty cycle data generated by the microcontroller 102, as well as to enable a user to perform diagnostics, change system settings, etc. A voltage regulator 114 is configured to supply a constant voltage level to a battery charger 116, which in turns supplies power to charge a battery 118 that is at least one of the power source for the microcontroller 102 and other circuit elements in the system 100. The microcontroller 102 may also be coupled to a wireless communication interface 120 that enable it to receive commands/instructions/code updates as well as transmit the hour, cycle count, and duty cycle data to an external/remote device that can be accessed by a user. The wireless communication interface may comprise Bluetooth, WiFi, cellular, and other technologies,

Not shown explicitly, the microcontroller 102 may also be coupled to ADC (analog-to-digital converter), DAC (digital-to-analog converter), one or more data communication interfaces such as UART (Universal Asynchronous Receiver-Transmitter), IrDA (Infrared Data Association), and SPI (Serial Peripheral Interface), I²C (Integer-Integrated Circuit), etc. to process/transmit/supply input and output to and from the microcontroller 102.

Accordingly, the system and method 100 described herein are configured to measure, obtain, and determine a number of operating parameters of a frac pump: number of operating hours, cycle count, and the duty cycle. For purposes of this disclosure, the number of operating hours is defined as the amount of time, in hours, that the pump is operating equal or above a certain predetermined speed threshold, for example 20 RPM. The cycle count is the number of times that a crankshaft of the pump has gone through a whole cycle. The duty cycle is the percentage of total time that the pump is in operation measured as in operation within a certain discharge fluid pressure range. Preferably, a desired output is a histogram of cycle count and operating hours for predetermined ranges of pump discharge pressure. For example, the pump may determine the pump cycle count and operating hours where the pump discharge pressure <10,000 psi, 10,000-11,000 psi, 11,000-12,000 psi, 12,000-13,000 psi, etc.

FIG. 2 is a pictorial representation of an exemplary positive displacement pump 200 as an exemplary monitoring subject for the system and method 100 described herein. The positive displacement pump 200 has two sections, a power end 202 and a fluid end 204. The fluid end 204 of the pump includes a fluid end block or fluid cylinder, which is connected to the power end housing via a plurality of stay rods 206. In operation, the crankshaft (not explicitly shown) reciprocates a plunger rod assembly between the power end 202 and the fluid end 204. The crankshaft is powered by an engine or motor (not explicitly shown) that drives a series of plungers (not explicitly shown) to create alternating high and low pressures inside a fluid chamber in the fluid end that entered the fluid end via a suction manifold 208. The cylinders operate to draw fluid into the fluid chamber and then discharge the fluid at a high pressure to a discharge manifold 210. The discharged liquid is then injected at high pressure into an encased wellbore. The injected fracturing fluid is also commonly called a slurry, which is a mixture of water, proppants (silica sand or ceramic), and chemical additives. The pump 200 can also be used to inject a cement mixture down the wellbore for cementing operations. The pump 200 may be freestanding on the ground, mounted to a skid, or mounted to a trailer.

Although described in the context of monitoring a frac pump, the system and method may be used to monitor a variety of equipment at a fracturing site. The system and method may also be used to monitor the operations of a slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), trailers upon which some equipment are carried, valves, wellhead, charge pump (typically a centrifugal pump), conveyers, and other equipment at the site of a hydraulic fracturing operation or other types of hydrocarbon recovery operations.

The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the system and method for comprehensive fracturing pump operations monitoring described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein. 

What is claimed is:
 1. A system for monitoring a hydraulic fracturing pump, comprising: a first sensor configured to measure a discharge fluid pressure of the pump; a second sensor configured to sense a displacement of a crankshaft of the pump; a processor communicatively coupled to the first and second sensors and configured to analyze the sensor data and determine a cycle count, duty cycle, and operating hour value for the pump; and a display coupled to the processor configured to display the cycle count, duty cycle, and operating hour value.
 2. The system of claim 1, wherein the processor is configured to determine a number of operating hours that the pump is operating at a speed equal or above a predetermined threshold.
 3. The system of claim 1, wherein the processor is configured to determine the number of hours the pump is operating within certain fluid discharge pressure ranges.
 4. The system of claim 1, wherein the processor is configured to determine the number of cycles the pump is operating within certain fluid discharge pressure ranges.
 5. The system of claim 1, wherein the first and second sensor is selected from the group consisting of pressure transducer, strain gauge, pressure sensor, accelerometer, vibration sensor, piezoelectric element, proximity sensor, linear variable displacement transducer, load cell, and flow meter.
 6. The system of claim 1, further comprising a wireless communication interface coupled to the processor.
 7. The system of claim 1, further comprising a data communication port coupled to the processor.
 8. A system for monitoring a hydraulic fracturing pump having a crankshaft, comprising: at least one sensor configured to measure at least one of a discharge fluid pressure of the pump, and a second sensor configured to sense a displacement of a crankshaft of the pump; and a processor communicatively coupled to the at least one sensor and configured to analyze the sensor data and determine a cycle count, duty cycle, and operating hour value for the pump.
 9. The system of claim 8, wherein the at least one sensor is mounted in at least an interior and exterior of the pump and is selected from the group consisting of pressure transducer, strain gauge, pressure sensor, accelerometer, vibration sensor, piezoelectric element, proximity sensor, linear variable displacement transducer, load cell, and flow meter.
 10. The system of claim 8, further comprising a display coupled to the processor configured to display the cycle count, duty cycle, and operating hour value.
 11. The system of claim 8, wherein the processor is configured to determine a number of operating hours that the pump is operating at a speed equal or above a predetermined threshold.
 12. The system of claim 8, wherein the processor is configured to determine the number of hours the pump is operating within certain fluid discharge pressure ranges.
 13. The system of claim 8, wherein the processor is configured to determine the number of cycles the pump is operating within certain fluid discharge pressure ranges.
 14. The system of claim 8, further comprising at least one wireless communication interface coupled to the processor.
 15. The system of claim 8, further comprising a data communication port coupled to the processor.
 16. A method for a comprehensive monitoring of operations of a hydraulic fracturing pump, comprising: receiving sensor data from at least one sensor configured to measure at least one of a discharge fluid pressure of the pump and a displacement of a crankshaft of the pump; analyzing the sensor data and determine a cycle count, duty cycle, and operating hour value for the positive displacement pump; storing the cycle count, duty cycle, and operating hour value; and wirelessly communicating the cycle count, duty cycle, and operating hour value to an external device.
 17. The method of claim 16, further comprising determining a number of operating hours that the pump is operating at a speed equal or above a predetermined threshold.
 18. The method of claim 16, further determining the number of hours the pump is operating within certain fluid discharge pressure ranges.
 19. The method of claim 16, further determining the number of cycles the pump is operating within certain fluid discharge pressure ranges.
 20. The method of claim 16, wherein receiving sensor data comprises receiving sensor data from at least one sensor selected from the group consisting of pressure transducer, strain gauge, pressure sensor, accelerometer, vibration sensor, piezoelectric element, proximity sensor, linear variable displacement transducer, load cell, and flow meter. 